Parameterization of equivalent circuit models for high power lithium-ion batteries in HEV applications

Detection of open circuit fault in battery power supply feeding permanent magnet synchronous motor

“…4). Hence, calculating (16) from (13)-(15) at steady state yields (22). The equation is further modified by calculating i DC from (its own) current components in d-q reference frame from (10)…”

“…In previous sections, the modelling has been performed assuming correct values of the quantities involved. However, in a real world all parameters and variables (voltages, currents, resistances) in (22) may differ from the assumed ones; hence a corresponding error ζ ε has to be added to the original equation (16), resulting in (23). It represents a deviation from ε owed to erroneous parametrisation, modelling and measurement.…”

“…Diagnostic algorithm should unequivocally detect the occurrence of a fault. Hence, a clear distinction between the error ε caused solely by the fault (22), and the one caused by the possible deviation of the very same ε (additional ζ ε in (23)), should be made. In order to encompass the worst-case condition, ζ ε has been conservatively set to its maximum possible value ζ ε_max .…”

Battery impedance measurement using sinusoidal ripple current emulator

“…Ah Li-ion battery for finding the minimum impedance point [20]. Therefore, the impedance parameters of the equivalent circuit of a battery are reflective of electrochemical reactions and transport processes [21]. There are different approaches available to measure the battery internal impedance: dc discharge, ac current injection method, sinusoidal duty perturbation in battery charger, and motor controller excitation method [22][23][24][25][26][27].…”

“…1.1 based on the dynamic characteristics of the electrode and electrolyte interface. This circuit model has been considered the battery dynamic characteristics such as diffusion, activation and concentration polarization, double layer capacitance impact, and Warburg impedance [14]. Typically, the ohmic resistance, R o is modeled based on the conductivity of the electrolyte and temperature.…”